The present invention relates to a camera with a night photography device which adjusts the exposure time and the focus of the taking lens system to such conditions as are suitable for taking pictures at night.
In an automatic exposure control device (hereinafter referred to as an AE device) incorporated in a compact camera, a CdS element (cadmium sulfide element) is widely used as a photosensor. Analog signals detected by this CdS element, which correspond to the brightness of a scene to be photographed, are converted to digital signals and supplied to a microcomputer which calculates the proper exposure time by using these digital signals and internal exposure parameters of the camera relating to exposure, such as film sensitivity and the like. Since in the lower range of brightness, the linearity of a CdS element deteriorates and its resistance becomes so high as to require too much time for A/D conversion of the detected signals, the exposure times set by such an AE device are limited at most to about 1/10 second. By using such a conventional compact camera with an exposure time limiting function, it is difficult to take a night view because a longer exposure time, generally more than 1/10 sec., is required. In particular, it is impossible to take pictures at night with such a compact camera loaded with ordinary film having a low sensitivity of ISO 100.